The present disclosure relates generally to repairing high temperature performance alloys, e.g. superalloys.
Metal and alloy parts may experience various wear instances as a result of application fatigue. For example, cracking, abrasions, erosion or a variety of other acts may cause the removal or wear of original substrate material. To repair the worn parts, filler material may be added (e.g., welded or brazed) to fill in cracks, patch abrasions or otherwise replace material lost to erosion or has become defective during operation. To provide strong uniform mechanical properties across the repaired parts, filler material that is the same as, or substantially similar to, the substrate material can be used.
However, high temperature performance alloys (such as nickel and cobalt based super alloys used in hot gas path components of gas turbine parts) have high melting temperatures that require a significant application of energy before they can be applied to the original substrate material. As a result, the large amount of heat produced by a welding apparatus used to melt such filler materials can also affect the nearby substrate material. For example, heat can cause slumping, melting or other changes to the microstructure of the original substrate material. These changes in the substrate material can reduce the original component's strength, toughness and/or other physical characteristics. While other filler materials with lower melting temperatures may alternatively be used, they may provide lower performance at high temperatures and/or possess mechanical properties that are increasingly different than the mechanical properties of the original substrate material. Additionally, the filler material may crack and lower the effectiveness of the repair.